Closed Knuckle Axle with disc's (is it possible?)
 

I have a 68 K-10 with the original closed knuckle front axle. Nobody sell a conversion kit for front discs and I thought that it was impossible. I have heard though that you can pull the parts off of a mid 70's 4x4 and place them on the closed knuckle..... Can Anybody confirm or deny this? I am getting ready to redo my drum brakes and this would change everything! Thanks...

Re: Closed Knuckle Axle with disc's (is it possible?)
 

yes it is, go junking and bring a measuring tape........

Re: Closed Knuckle Axle with disc's (is it possible?)
 

I am in the same boat and would like to know more specifics on this mod.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

Here's what I know from converting my open-knuckle '69 to disc brakes. With proper use of a grinder for clearancing you can use drum knuckles, if I recall correctly you have to grind a notch in the knuckle to clear the caliper properly. Reason for this is the disc-brake studs are clocked differently and thus the backing plates put the caliper in contact with a part of the knuckle. You will need the spindles, rotor/hub, backing plates, and all caliper hardware.

Best bet is to get 73+ brakes for ease of finding cheap parts, if you want to keep standard fittings get 73-77 parts, 78-79 calipers are a crap-shoot between 3/8 and 10mm, 1980+ are all 10mm.

When I did my swap I pulled the knuckles off an '82, I know that isn't an option for you. I did keep the original outer axle shaft, and drum shafts are about 1/4" short due to a slight difference of the bearing location within the hub assembly. You cannot swap the outer shafts from the 73+ trucks because the u-joint is a larger size; you *could* use 71-72 outer axle shafts to fix this but finding them will be tough. The net effect is that the snap-ring that retains the manual locking hub innards will not seat. Solution is to use a 7/16" fender washer and a 7/16"-20 x 1" long bolt to screw into the end of the axle shaft (it is threaded).

Hope that gets you started.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

This past summer I tried this swap on my k20. It didnt work with the parts I used. I pulled everything off a 79 k20 10bolt (spindles, hubs, backing plate, rotors, calipers) They all fit the axle great until I tried to fit the caliper on the backing plate. The caliper hits the ball for the closed knuckle. The closed knuckle really interferes with the caliper so grinding for clearance isnt an option. For now I am just looking for a open knuckle D44 in ND to swap.

I have switched to boosted drums until I get discs and that has made a huge difference over unboosted.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

ND_guy,
What type of booster did you use and what all is needed to complete this task. I have a '68 K-20 that I definately need to do this to. Thank's for your input.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

I used Hydroboost out of 80 1ton van. It wasnt a bolt in system I made custom lines, pushrod and mounting brackets for the booster and used the van power steering pump.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

Thanks, I'll keep that in mind.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

I may just go for the booster setup from a disc truck and redo my drums until I tear the truck apart someday and look at an axle swap.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

Good info about hitting the ball, I never thought that it would be that close.

A point to note, between all the parts I had to buy to make my junk work (balljoints, fancy brake lines, new calipers, etc) I spent more than if I had simply bought a 73+ axle complete and swapped it under my truck. My issue at the time was that I could not find one with the right gear ratio, so instead I decided to tear mine apart. Later I did find one for less than $300, and it would have basically been a bolt-in.

Food for thought.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

What axle ratio would my 68 K-10 have?

Re: Closed Knuckle Axle with disc's (is it possible?)
 

For what it is worth, I have a vaccuum boost on my 69, unknown source that PO installed. He said that made all the difference in stopping or not. It works good, the only problem with the drums is that they are real hard to find or expensive.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

If you're lucky it will still have the tag on it. There should be a small metal tag attached at one of the bolts on the differential, which will give you the ratio. Otherwise, it involves counting teeth on gears, and some math. Something someone more experienced than me needs to explain, I got lucky and had the tag on mine (3.54).
I would be interested in knowing if there is an easier way, it would help when I go junkyarding for this project.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

the 1/2's are different, if any body wants to come down, move a few parts and 2 trucks, pull a wheel you can take all the pictures of the conversion you want.
The major hard part is getting the spindle off of the steering knuckle. Need the proper tool and a slide hammer, penetrating oil and sometime a little heat.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

I just use a dead-blow, or a real hammer and a block of wood? I've removed 4 of them that way, all rusted pretty decently. The slide-hammer trick would be pretty cool, I'd think you'd need some strong arms to get it out that way.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

Yes it is possible..:)

http://www.blackbirdscustomtrucks.com/index25.html

Re: Closed Knuckle Axle with disc's (is it possible?)
 

that says 3/4 ton, will it work with 1/2 ton 6 lug closed knuckle? Do you have a total kit then?

Re: Closed Knuckle Axle with disc's (is it possible?)
 

I must be blind.. for some reason I didn't notice you needed half ton..

We are waiting to get a front diff to build one off of it. So as for now.. No.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

OK I am interested. I am a machinist with lotsa experienceeo and I have not a lotta denerio ( dollas!)!! Blackbird, if you could, peice meal me a kit in some form as I gather parts from this or that and do this or that to make it happen????? Like , what I meana is would ya work witha mea????:cool:

Re: Closed Knuckle Axle with disc's (is it possible?)
 

Thats like asking a restaurant for thier secret sauce by asking for one ingrediant at a time....

We are the only company right now to make this as an option for the closed knuckle. I am very sorry, but I am not going to tell you what you need to make this kit..

Re: Closed Knuckle Axle with disc's (is it possible?)
 

I am truly sorry that I misunderstood this thread. I thought this was a posting of information to do this mod and for those helping others to give that info.
I did not expect this to be solely an ad for a kit for sale only!

expect this post to be banned.:crazy:

Re: Closed Knuckle Axle with disc's (is it possible?)
 

The post I started was searching for information to do the mod, drink2meny is a vendor on the site and has a similar kit that he was informing us about. I didn't know that anyone was making these so that's great. (I plan to buy when he get a 1/2 ton model). Asking a vendor for his plans isn't what this was about, asking another member their technique for a mod is normal....

Re: Closed Knuckle Axle with disc's (is it possible?)
 

I wll check with my fellow mods and see if I crossed the line.
All I did was answer what the main question of what title ask.

I didn't take time to read through the whole post, so hang a brother..
msgross, sorry.. didn't mean to take away from your original post.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

no problem here, I think that he's upset or something...

Best solution for the brakes is to swap with a newer style axle (150-200 @ junk yard?), that is until you invent a kit for 1/2 tons.

Re: Closed Knuckle Axle with disc's (is it possible?)
 

No one upset here. Just expect that if we are discussing mods............then that,s what we do.. I was just asking to get info....... not looking to be insulted in front of the rest here.
I don't recall anyone saying there was a "secret ingredient" here at the get go, so I figured it was fair to ask and not made to look stupid after I ask!!!!:o